Rotary barrel pick-up in automatic plating apparatus

ABSTRACT

An improved rotary barrel pick-up system on automatic electroplating apparatus which includes as a basic unit, a first drive motor for rotating a plating barrel within a tank containing electroplating fluid. The first motor is mounted on the tank and rotates a drive shaft which is mounted on a frame supporting the barrel. A hoist for lifting the barrel from the tank and depositing it in another tank includes means for rotating the barrel after it is lifted out of the plating fluid and means for preventing substantial translational movement of the frame relative to the hoist. Functionally, the improved means for moving the barrels from tank to tank lends itself to simplified movement without human assistance at the tank site.

United States Patent H 1 [111 3,862,896 Singleton 1 Jan. 28, 1975 ROTARY BARREL PICK-UP [N Primary Examiner.lohn H. Mack AUTOMATIC PLATING APPARATUS Albert Singleton, 7360 Brookside Park. Middlehurg Heights. Ohio 44l30 Filed: July 20, 1973 Appl. No.1 380,968

Inventor:

References Cited UNITED STATES PATENTS 7/]963 Pianowski I34/46 ll/l966 Kumpf 134/140 Assistant Examiner-Aaron Weisstuch Attorney, Agent, or Firm-Fay & Sharpe; Sidney W.

Millard ABSTRACT An improved rotary barrel pick-up system on automatic electroplating apparatus which includes as a basic unit, a first drive motor for rotating a plating barrel within a tank containing electroplating fluid.

The first motor is mounted on the tank and rotates a drive shaft which is mounted on a frame supporting the barrel. A hoist for lifting the barrel from the tank .ment without human assistance at the tank site.

10 Claims, ll Drawing Figures ROTARY BARREL PICK-UP IN AUTOMATIC PLATING APPARATUS BACKGROUND OF THE INVENTION This invention has to do with automatically controlled electroplating apparatus and more particularly, is concerned with the lifting and rotation of electroplating barrels after said barrels are lifted out of the plating fluid in a particular tank.

Electroplating barrels are traditionally circular or polygonal in cross section and as a general rule their sides are relatively thick. The sides are actually a sieve-type structure having a plurality of small apertures therethrough. The purpose is to allow the flow of electric current and free movementof the ion containing electroplating fluid into and out of the plating barrel.

While the barrel is in the electroplating fluid, the heavy metallic load to be plated is within the barrel and agitation of the fluid as well as the barrel contents is accomplished by a motor uniquely connected to turn the drum while it is immersed in the plating fluid. Thus, the articles within the barrel tumble over and over for full exposure to the plating fluid as the barrel rotates.

When the time comes to lift the barrel from the plating fluid and transport it to the next tank for a different plating or washing process, one must be concerned with the amount of fluid retained in the barrel itself. Often the goods being plated contain recesses or have some cup-shaped portion and thus, they can hold some fluid. Should the parts to be plated be relatively small, the apertures through the sides of the barrel will'also be small to prevent the articles from falling through. Fluid within these small perforations will not flow completely back into the tank. Rather a meniscus will form due to surface tension. As can be seen, where the walls are up to an inch thick, a relatively large amount of fluid can be retained in the apertures through the sides of the barrel. In addition to the fact that a large amount of fluid will be removed from the tank by the barrel by this process, it will be recognized that the fluid retained in the barrel will also be a contaminant for the next tank in the plating process if the next fluid is not calculated to be identical in chemical makeup.

To solve this problem, the art has suggested a number of ways to continue the rotation of the barrel after it has been lifted out of the plating fluid of a particular tank. In this manner, the tumbling and bumping of the items being plated, will dump fluid from any recesses therein and in addition will jar the fluid lodged in the sidewall apertures such that the surface tension will be inadequate to retain the fluid in the apertures. Thus, it will drip and drop out into the barrel. Several of the uniquely designed structures to accomplish this service include a motor designed to continue the rotation of the barrel. Unfortunately none of them work except this one. The problem which exists in the art as a result of this rotation above the tank is that the combination of the twisting motor and the moment exerted by the articles in the barrel combine to disengage the barrel from the lifting bracket of the hoist with the result that the barrel may fall or 6 feet and be severely damaged as a result. All the other possibilities and lost equipment may easily be visualized. Thus, the need in the art is for some structure which will drain the electroplating fluid from the barrel in some manner but, will not dump the barrel on the floor. The solution to that problem is the subject matter of this invention.

When the barrel is rotating and tumbling elements within and being supported along its longitudinal axis of rotation, the tumbling elements will always be off center. Their combined weight times the average lever arm between their center of gravity and a vertical line passing through the axis of the drum is always acting to rotate the drum in a direction opposite to that in which it is in fact rotating as a result of power transmitted through the drive shaft. This fact is true whether the drum is being rotated within the tank or whether it is being rotated by some other means after it has been lifted completely out of the tank. Special blocks on the tank edges prevent translational movement of the barrel within the tank. But, once the barrel holding frame rises above the blocks there is nothing to prevent the moment from moving the barrel transversely.

BRIEF DESCRIPTION OF THE INVENTION Conventional electroplating apparatus includes a tank filled with electroplating fluid. The tank has a drive motor mounted along one side. The rotatable drum is suspended for rotation within the tank on a frame which includes some sort of mechanism on its upper end suitable for engagement and lifting to remove the barrel from the tank. In automatically controlled electroplating systems the apparatus mounted on the upper portion of the frame: is a bracket suitable for an engagement with a cooperatively shaped bracket mounted on the lifting means. The liftingmeans will move horizontally along a line of plating tanks until it comes to a stop as indexed by the automatic control apparatus. The stopping point will be such that the cooperatively shaped bracket on the lifting apparatus is below the bracket on the tank frame support. The lifting bracket rises and the barrel is lifted vertically until it will clear the tank and it will be held there until such fluid as will drain, has drained from the drum into the tank.

This invention incorporates a second drive motor adapted to be actuated and directly or indirectly connected to drive the drive shaft at approximately the point in time which the drive shaft is disengaged from the first drive motor on the side of the tank. Thus, as the barrel is lifted, it will continue to turn with the articles continuing to tumble within the barrel and the barrel will be held in place above the tank a few seconds until any fluid trapped within the barrel in the tumbling articles and the porous sides has drained back into the tank. I

To prevent the second drive motor from driving the frame bracket off the supporting bracket as a result of the turning moment imparted by the motor and the offcenter articles in the barrel, this invention provides side flanges alongside the engaging gear of the second drive motor and deep pockets on the brackets which have sides perpendicular to the direction of force resulting from the aforementioned moment.

Functionally, the improved means for moving the barrels from tank to tank lends itself to simplified movement without human assistance at the tank site.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational section of one embodiment of the invention;

FIG. 2 is an elevational view ofa modification of FIG. 1;

FIG. 3 is a fragmentary view partially in section taken along line 3-3 of FIG. 1; I

FIG. 4 is an elevational view taken along line 4-4 of FIG. 1; I I

FIG. 5 is a plan view partially in section taken along line 5-5 of FIG. 1;

FIG. 6 is an elevational view partially in section taken along line 6-6 of FIG. 1;

FIG. 7 illustrates a modification of the apparatus shown in FIG. 6;

FIG. 8 is a modification of the apparatus shown in FIG. 6;

FIG. Q is another modification of the apparatus shown in FIG. 6; and

FIG. 10 is yet another modification of the apparatus illustrated in FIG. 6.

FIG. 11 is a fragmentary perspective view taken along line 1l-l1 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 illustrate different embodiments of this invention. However, they contain much the same apparatus, it has merely been reoriented in the two different embodiments. Hereinafter, like elements in the two embodiments will be assigned the same identifying numeral and the differences in the structure between the two illustrated embodiments will be discussed in detail.

All electroplating apparatus includes a tank 10 filled with some fluid 12 and within the tank is a rotating barrel l4. Aconventional framework 16 supports the barrel 14 within the tank and it in turn is supported and centered within the tank by appropriate structure on the upper tank edges, not specifically illustrated in these drawings.

A V-belt, chain or other equivalent structure 18 running between a drive shaft 20 and the axis of rotation of the barrel 14 serves to rotate the barrel within the tank when the shaft 20 is driven. A first motor 22 and torque converter 24' are mounted along one side of the tank 10 in conventional manner. Other structural features to mount these elements in cooperative relationship and in engagement with gear 26 on one end of the drive shaft 20 are illustrated somewhat schematically as they comprise no specific part of this invention, although they are covered by patents previously issued to the inventor.

Turning now with more particularity to FIG. 1, an automatic lifting and conveying hoist is illustrated above the tank suspended by roller wheels 28 on a pair of I- beams 30. A cross bar 32 at the top, may support a hoist motor 34 having a depending hook 36. The hook 36 is illustrated in phantom at the top and in solid at the bottom in FIG. 1 to illustrate the extremes in its upward and downward movement. Obviously, cables or chains extending from the motor 34 to the book 36 provide the strength for lifting the barrel 14 from the tank 10.

Depending bracket 38 extends downward from a cross beam 40 which extends between a pair of parallel shafts 42. The cross beam 40 is held in position by guide rollers 44 which roll freely on shafts 42. Depending bracket 38 is illustrated in plan view in FIG. 5 and includes a depending I-beam 46 which may be welded to cross beam 40 and to plate 48. Lifting bars or rods 50 project horizontally from the plate 48 in a triangular pattern, each designed to be lifted into a pocket 52 formed by U-shaped elements 54 as part of the upstanding bracket means 56 affixed to the upper end of frame 16.

In operation the cross beam will be lowered as shown in FIG. 1 such that depending bracket 38 will have bars 50 below the mouth opening to pockets 52 in brackets 56. In this manner the lifting mechanism consisting of the hoist, cross beam 40, etc. may all move as a unit on the supporting l-beams 30 with the depending bracket passing along beneath all of the brackets 56 until the indexed automatic control means triggers a stop and subsequent lifting into the engagement as illustrated in FIG. 6.

Considering now FIG. 6 and the illustrated modifications in FIGS. 7-10, it will be important to recognize the similarity in these equivalent embodiments. In each case, there is specific structure which prohibits disengagement and this is perhaps best illustrated in comparison to the prior art.

Prior art devices, in attempting to provide a solution to the need to rotate the drum after it is lifted out of the electroplating fluid have used cooperating V'shaped lifting brackets and they have been universally unsuccessful. And for what would appear to be a very simple reason, when one considers elementary physics. However, for some reason, adequate structure has not been designed heretofore which would prevent the second drive motor from pushing the V-shaped portion of the barrel frame bracket out of the V-shaped portion of the lifting bracket.

Consideration should now be given as to why this happens and as has been pointed out previously, when the barrel is turning, the tumbling elements are inherently pulled upward and to one side of the barrel in the direction of rotation. The weight of this tumbling mass times the horizontal distance from the center of rotation of the barrel is opposing the rotation of the barrel in that direction and tending to turn it in the opposite direction. Thus, the motor must overcome this counter rotational force to continue the turning of the barrel. The force needed to do that is proportional to the radius of the drive gear 60 of motor 62 as illustrated in FIG. 3. In other words, to keep the barrel turning as it has been lifted, the force exerted by the motor 62 times the lever arm (or radius of the gear must exceed the force exerted by the weight of the tumbling elements times the lever arm or distance from their center of gravity to the horizontal centerline of rotation of the drum. As a result, the only additional holding points between the barrel frame and the lifting apparatus in addition to the gear engagement are the brackets.ln the absence of an equal force parallel to the moment tending to turn the drum and frame, the force will have a vertical as well as a horizontal component which will instantly be translated into a force parallel with one side of the V-shaped holding brackets and the gear will drive the cooperatively shaped bracket right up the side of the other V-shape and drop the barrel on the floor.

Before turning back to FIGS. 6-10, consider the side plates 64 attached to each side of the torque converter 66 alongside the drive gear 60. When depending bracket 38 is lifted into engagement with brackets 56, the gear 68 on the left hand end of drive shaft 20 as illustrated in FIG. 1, will be lifted into engagement with gear 60 (FIG. 3). Side plates 64 at this point in time, will prevent the gear 68 from twisting up one side or the other of the gear 60 because, they extend downwardly more than the radius of the gear 68. Thus, one side plate will exert an equal and opposite force on gear 68 and no twisting results.

Now observing FIGS. 6-10, one can observe that the pocket effect of the cooperatively shaped bracket means includes a vertically extending wall in all cases having a flat holding surface which will immediately oppose the direction of movement of the barrel frame bracket. As will be equally obvious now that the principles have been explained, a sloped or curved surface having any angle or any slope other than a truly flat vertical surface will allow some component of force to be translated along that slope and will allow the drive motor to drive the two brackets apart.

In particular, structure equivalent to that in FIG. 6 consisting of a T-shaped element 70 is illustrated in FIG. 7 and has been substituted for the circular rod 50 in FIG. 6; in FIG. 8 the two bracket elements 72, 74 are both U-shaped: FIG. 9 illustrates the same elements as in FIG. 6 but, with the rod 50 and the U-shaped element 54 inverted; and FIG. illustrated a pin 76 projecting upwardly through an aperture 78. In all cases, the illustrations in FIGS. 6-10 are functional equivalents although, the illustrations in FIGS. 6 and 9 are preferred.

Turning now to the specific structure and mounting of the motor 62 in FIGS. 1, 3 and 4, it will be observed that a downwardly extending arm 80 allows the motor to fall by gravity to its lower end where it is stopped by a pin 82. Conventional guide rollers 84 ride up and down the arm 80. When the gear on drive shaft is lifted into engagement with gear 60 the motor 62 will ride upwardly as the hoist lifts the drum. This is accomplished by a projection 86 best illustrated in FIG. 1. The block 86 is designed to rest on the top of frame 16 and ride upwardly as the frame is lifted. The block 86 is necessary to prevent the jamming of the gear teeth of gears 60 and 68. Gear teeth are not designed to bear the load of the motor 62. As best illustrated in FIG. 11 pins 85 penetrate apertures 87 in plate 89 as the frame is lifted and in this manner help prevent misalignment of the gears as well as the lifting structure.

FIG. 2 illustrates the same side bars 42 and cross beam 40. However, it will be noted that the bracket 88 mounted on frame 16 and the brackets 90 mounted on cross beam 40 are the inverted equivalent of brackets 38 and 56 of FIG. 1. No further explanation appears necessary. The true distinction in this modification is not in the bracket means itself but rather the mounting of the second drive motor 92.

The particular design of the motor lifting mechanism in FIG. 1 requires rather close tolerances and often it is better to use the mechanism illustrated in FIG. 2 where the second drive motor 92 is directly mounted on the cross beam 40 and lifts upward such that the drive gear 94 meshes with drive gear 96 which, in turn drives a chain 98 connected directly to the drive shaft 20. As will be obvious in this embodiment as well as in FIG. 1, a slip clutch 100 may be incorporated to prevent the second drive motor from fouling the rotation imparted by the first drive motor 22 before the gear 26 is lifted out of operative engagement with the first drive motor.

Modifications of this invention will be obvious to those having ordinary skill in the art. For example, motor 92 could be mounted above cross beam 40 and a chain or other kind of drive designed to turn another gear which would mesh with gear 96. Also the motor 92 could be mounted on frame 16 and a lifting mechanism on cross beam 40 designed to trip an on-off mechanism or rotate a drive wheel into place to begin the turning subsequent to the disengaging of gear wheel 26.

Other modifications will certainly be obvious to those having ordinary skill in the art which fall within the spirit of this invention.

I claim:

1. In the combination of a rotary electroplating barrel a frame for supporting said barrel for rotation within tanks containing liquid used in electroplating, a drive shaft mounted in said frame, a drive shaft engaging means for converting drive shaft rotation to barrel rotation, a first drive motor means for turning the drive shaft, said motor means being mounted in stationary position adjacent each said tank, means for raising and lowering said frame and barrel to move them from one tank to another, said tanks being aligned beneath track means supporting a second frame, said second frame comprising a part of said raising and lowering means, a second drive motor means mounted on the second frame for rotating the drive shaft and barrel only between the times the drive shaft is moved out of operative engagement with the first drive motor means and the time it re-engages the first or a similar motor means, the improvement comprising:

first bracket means rigidly attached to the barrel supporting frame and second bracket means rigidly attached to the second frame, both said bracket means being for cooperative engagement to connect the frames during the lifting and lowering of the barrel,

the portion of the first bracket means which engages the second bracket means extends above all adjacent portions of the barrel supporting frame,

the engaging portion of the second bracket means in its lowermost position extends below all adjacent portions of the second frame and below the engaging portions of the first bracket means whereby the second bracket means and second frame will move horizontally along said track means without contacting the barrel supporting frame or the first bracket means and,

said second frame and said second bracket being rigidly connected together to prevent lateral movement of the second bracket relative to said track.

2. The combination of claim 1 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system, I

the second bracket being mounted to move along a horizontal path until it is lifted into contact with one of a plurality of first brackets.

3. The combination of claim I wherein the raising means includes a lifting motor means connected for lifting the second bracket into contact with the mating first bracket on the barrel supporting frame,

one of said brackets including a vertically extending surface means for engaging the other bracket such that the moment of rotation exerted by l the second drive motor means and (2.) the combination of the weight of the barrel and its contents, cannot push the brackets out of supporting engagement.

4. The combination of claim 3 wherein one of said brackets comprises U-shaped elements arranged to receive cooperatively shaped bars on the other bracket.

5. The combination of claim 4 wherein the second drive motor is mounted on the raising means to move vertically with said second bracket.

6. The combination of claim 5 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system,

the second bracket being mounted to move along a horizontal path until it is lifted into contact-with one of a plurality of first brackets.

7. The combination of claim 3 wherein the second drive motor is mounted on the raising means to move vertically with said second bracket.

8. The combination of claim 7 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating systerm the second bracket being mounted to move along a horizontal path until it is lifted into contact with one of a plurality of first brackets.

9. The combination of claim 4 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system,

the second bracket being mounted to move along a one of a plurality of first brackets.

* a t 4* k 

1. In the combination of a rotary electroplating barrel a frame for supporting said barrel for rotation within tanks containing liquid used in electroplating, a drive shaft mounted in said frame, a drive shaft engaging means for converting drive shaft rotation to barrel rotation, a first drive motor means for turning the drive shaft, said motor means being mounted in stationary position adjacent each said tank, means for raising and lowering said frame and barrel to move them from one tank to another, said tanks being aligned beneath track means supporting a second frame, said second frame comprising a part of said raising and lowering means, a second drive motor means mounted on the second frame for rotating the drive shaft and barrel only between the times the drive shaft is moved out of operative engagement with the first drive motor means and the time it reengages the first or a similar motor means, the improvement comprising: first bracket means rigidly attached to the barrel supporting frame and second bracket means rigidly attached to the second frame, both said bracket means being for cooperative engagement to connect the frames during the lifting and lowering of the barrel, the portion of the first bracket means which engages the second bracket means extends above all adjacent portions of the barrel supporting frame, the engaging portion of the secoNd bracket means in its lowermost position extends below all adjacent portions of the second frame and below the engaging portions of the first bracket means whereby the second bracket means and second frame will move horizontally along said track means without contacting the barrel supporting frame or the first bracket means and, said second frame and said second bracket being rigidly connected together to prevent lateral movement of the second bracket relative to said track.
 2. The combination of claim 1 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system, the second bracket being mounted to move along a horizontal path until it is lifted into contact with one of a plurality of first brackets.
 3. The combination of claim 1 wherein the raising means includes a lifting motor means connected for lifting the second bracket into contact with the mating first bracket on the barrel supporting frame, one of said brackets including a vertically extending surface means for engaging the other bracket such that the moment of rotation exerted by (1) the second drive motor means and (2) the combination of the weight of the barrel and its contents, cannot push the brackets out of supporting engagement.
 4. The combination of claim 3 wherein one of said brackets comprises U-shaped elements arranged to receive cooperatively shaped bars on the other bracket.
 5. The combination of claim 4 wherein the second drive motor is mounted on the raising means to move vertically with said second bracket.
 6. The combination of claim 5 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system, the second bracket being mounted to move along a horizontal path until it is lifted into contact with one of a plurality of first brackets.
 7. The combination of claim 3 wherein the second drive motor is mounted on the raising means to move vertically with said second bracket.
 8. The combination of claim 7 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system, the second bracket being mounted to move along a horizontal path until it is lifted into contact with one of a plurality of first brackets.
 9. The combination of claim 4 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system, the second bracket being mounted to move along a horizontal path until it is lifted into contact with one of a plurality of first brackets.
 10. The combination of claim 3 wherein the electroplating tank and barrel are each one of a series of similar articles arranged in an automatic electroplating system, the second bracket being mounted to move along a horizontal path until it is lifted into contact with one of a plurality of first brackets. 